I've played most of them to some extent or another, but Matrix Cubed is the only one I actually finished
. The others were great, I'm sure, but most of them never held my attention. Of the others, the one I've played most was PoR -- I remember cracking open that gold box (on a Commodore 64!), and being floored at playing D&D
on my computer! (At, what, 11 or 12 years old?) But soon, as I got more and more lost in it, it lost me.
Off topic, for what it's worth, I went through the same thing when I recently tried Elder Scrolls: Morrowind. I'd beaten the death out of Oblivion (and loved every minute of it), but when I saw how difficult it was to follow what you should
be doing in Morrowind, it totally lost me.
I like games that, somehow, remind me of what I'm supposed to do.